Toxicity of intravesical BCG and its management in patients with superficial bladder tumors

Toxicity of bacillus Calmette‐Guerin (BCG) Pasteur strain, given in a dose of 120 mg once a week for 6 weeks, was retrospectively evaluated in a study of 107 patients with recurrent superficial bladder cancer. Only six patients had no symptoms of toxicity. Severe cystitis (ten patients) was most likely to occur in those with decreased bladder compliance before treatment. Systemic symptoms resembling those of influenza (flu) were severe in six patients. Potentially serious complications occurred in six patients. Overall, toxic reactions were mild and self limited, and toxicity often could be easily managed by a reduction in the BCG dose (17 patients), temporary interruption of treatment (five patients), or cessation (four patients). Late occurrence of bladder granulomas (32 patients) and cystoscopic appearance of significant cystitis (55 patients) did not correlate with posttreatment voiding symptoms, and these changes were temporary and confined to the first 6 months after treatment. There were no cases of late bladder contracture, and none of the patients free of voiding symptoms before treatment had such symptoms afterward. Extravesical granulomas were observed in 37 patients and were the cause of obstruction of the urinary tract in nine. Pretreatment skin reactivity did not correlate with toxicity, and concurrent percutaneous administration of BCG had no effect on toxicity. BCG has a cumulative effect, so increased toxicity is to be expected during long‐term administration. BCG toxicity is primarily a response of the cell‐mediated immune system, and transient local or systemic infection appears to be important. This fact suggests that immunosuppression is a relative contraindication to BCG use.